This invention relates to a process, and an apparatus, for the indexing and retrieval of data.
There are many known systems for indexing and retrieving information. At one extreme, there are simple sets of sequentially arranged record cards, which are up-dated and searched directly by a user. At the opposite extreme, there are the highly sophisticated systems in which the data is stored in computerised form on, for example, magnetic disc files. The up-dating and searching of data with such a system will probably be carried out by means of a large computer system. The user will communicate with the system by means of a visual display unit, or other form of data terminal.
There have also been proposals for systems in which data is recorded in microfilm, or microfiche, form and each unit of data on the film is accompanied by an encoded recording. This recording would be a bar code representative of a unit serial number, in a typical case. The code representation can be sensed optically to allow automatic selection of a desired unit of data. A system of this last-mentioned kind in which an encoded recording accompanies the film is less expensive than a large computerised system. However, it does require a substantial investment in equipment and also requires skilled staff to operate the system.